The Food and Drug Administration on May 6 cleared the KeyPath MRSA/MSSA blood culture test, which can quickly determine whether the Staphylococcus aureus infection is methicillin resistant (MRSA) or methicillin susceptible (MSSA).
"This not only saves time in diagnosing potentially life-threatening infections but also allows health care professionals to optimize treatment and start appropriate contact precautions to prevent the spread of the organism," Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics Device Evaluation and Safety in the FDA’s Center for Devices and Radiological Health, said in a statement.
The test determines MRSA or MSSA infections within 5 ½ hours directly from gram-positive blood cultures. The test does not require any specific or additional instruments aside from blood culture equipment, according to the FDA.
Identifying whether an S. aureus infection is MRSA or MSSA currently takes a day or more, depending on the organism and whether the laboratory is on site or not, said Dr. Donna E. Sweet, professor of internal medicine at the University of Kansas, Wichita. "So, this is good news," she said in an interview.
"Any time you can know [the results] sooner than later, then it decreases [patients’] exposure to more potent antibiotics. A quick test will help you narrow your antibiotic focus more quickly and target the bug more quickly," said Dr. Sweet, who is not affiliated with the test or its manufacturer.
The clearance was based on a clinical study of 1,116 blood samples at four major U.S. hospital centers. The test’s accuracy was 98.9% for detecting MRSA (178/180) and 99.4% for MSSA (153/154).
National statistics show that the rate of MRSA infections in the United States is falling. However, it remains an "important public health problem," according to the Centers for Disease Control and Prevention.
The test is manufactured by MicroPhage Inc.